Exhaust Gas Purification System and Method and Data Processing System for Monitoring at least One Exhaust Gas Pufication System

ABSTRACT

The present invention relates to a computer-implemented method for monitoring at least one exhaust gas purification system for purifying an exhaust gas stream to be purified of an industrial system or an industrial process. The method comprises retrieving system data of the exhaust gas purification system from a data cloud. The system data stored in the data cloud were at least partially received beforehand by the data cloud from the exhaust gas purification system. The system data relate to at least measurement data of at least one sensor of the exhaust gas purification system and/or data about at least one adjustable parameter of the exhaust gas purification system. The method further comprises determining at least one quantity characterizing the exhaust gas purification system based on the retrieved system data.

The present invention relates to monitoring of exhaust gas purification systems. In particular, the present invention relates to a computer-implemented method and a data processing system for monitoring at least one exhaust gas purification system and to an exhaust gas purification system itself.

Exhaust gas purification systems are used for purifying an exhaust gas stream or an exhaust air stream. During operation of an exhaust gas purification system, a variety of data points are collected or generated by the exhaust gas purification system itself. These data points are analyzed or evaluated in order to enable a monitoring or characterizing of the exhaust gas purification system. For this purpose, the data are conventionally stored on a local storage medium (e.g., memory card, portable hard disk or USB stick) coupled to the exhaust gas purification system and then evaluated manually by qualified personnel. For example, recorded measurement data may be visualized by qualified personnel by means of special software, or quantities of interest may be calculated or estimated by means of partly extensive calculations.

The legacy evaluation of the data points generated by the exhaust gas purification system substantially limits the determination of the state of the system to the current and/or past state. Likewise, the evaluation of the data points is only possible with appropriate specialist knowledge and at a considerable expenditure of time. Also, the data points are usually only available locally at the system, so that a direct access to the system is required for the evaluating qualified personnel.

In view of the above, one object of the present invention is to provide an improved possibility for monitoring exhaust gas purification systems.

The object of the invention is solved by a computer-implemented method and a data processing system for monitoring at least one exhaust gas purification system as well as an exhaust gas purification system according to the independent claims. Further aspects as well as further developments of the invention are described in the dependent claims, the following description and in the figures.

According to a first aspect, the invention relates to a computer-implemented method for monitoring at least one exhaust gas purification system. An exhaust gas purification system is a system that removes impurities or one or more pollutants from a fed exhaust gas stream or exhaust air stream so that a purified exhaust gas stream may be transmitted from the exhaust gas purification system. The purified exhaust gas that is transmitted from the exhaust gas purification system is often also referred to as purified (clean) gas. The exhaust gas stream or exhaust air stream to be purified, which is fed into the exhaust gas purification system, may originate from an industrial system or an industrial process of the chemical, petrochemical, pharmaceutical or solvent processing industries, for example. A pollutant may be understood in this context as a substance that harms plants, animals, humans and/or the environment when occurring in a specific quantity or concentration (e.g., defined as mass of the pollutant per unit volume of the exhaust gas stream or exhaust air stream or as number of pollutant particles per unit volume of the exhaust gas stream or exhaust air stream). Accordingly, the purification of the exhaust gas stream or exhaust air stream may include, e.g., a detoxification, denitrification, deacidification, desulfurization, dedusting or a combination thereof. For example, organic and/or inorganic pollutants may be removed from the exhaust gas stream or exhaust air stream by the exhaust gas purification system. An exhaust gas purification system may be used for removing, e.g., solvents, nitrogen oxides (NO_(x)), sulfur oxides (SO_(x)), hydrogen fluoride (HF), ammonia (NH₃), hydrogen chloride (HCl), dioxins, furans or pollutants of the basic structure C_(x)H_(y)O_(z) (C denotes carbon; H denotes hydrogen; O denotes oxygen; x, y, and z are natural numbers) from the exhaust gas stream or exhaust air stream.

The exhaust gas purification system may use various methods to purify the exhaust gas stream or exhaust air stream. For example, the exhaust gas purification system may use known concentration methods (e.g., by means of absorption, adsorption or membranes), condensation methods, catalytic methods, non-catalytic-chemical methods, methods using a non-thermal plasma (cold oxidation), biological methods (e.g., bioscrubbers, biofilters), mechanical methods, electromechanical methods, thermal methods or a combination of several of the abovementioned methods. Concentration methods may be used in combination with another method, in particular methods for exhaust gas purification. For example, concentration methods may be used together with a condensation method (e.g., for solvent recovery) and/or an oxidative method for pollutant conversion (e.g., thermal and/or catalytic oxidation for pollutant disposal). An exhaust gas purification system using a catalytic method may, for example, comprise monolithic catalyst elements and/or catalytically activated filter elements (e.g., ceramic filter cartridges or fabric filters) for purifying the exhaust gas stream or exhaust air stream. An exhaust gas purification system using a thermal method may purify the exhaust gas stream or exhaust air stream, e.g., via recuperative thermal oxidation (Germ. TNV=thermische Nachverbrennung), regenerative thermal oxidation (RTO), direct-fired thermal oxidation with subsequent waste heat utilization or by substituting the oxidation air of a process heat generation facility with the exhaust gas stream or exhaust air stream. Alternatively or in addition, the exhaust gas purification system may also use separation processes in cyclone separators, filtering devices, electrostatic precipitators and/or scrubbers for (further) exhaust gas purification.

The inventive method comprises retrieving of system data of the exhaust gas purification system from a data cloud (cloud storage or cloud computing). A data cloud denotes the provision of IT infrastructure, such as memory space, computing power or application software as hosted services over the Internet and/or at least an intranet. According to embodiments, the data cloud may in this context also be built up from several instances of (sub-) data clouds or comprise several instances of (sub-) data clouds. For example, the data cloud may include an intranet data cloud at the location of the exhaust gas purification system or a cross-site intranet data cloud of an operator of the exhaust gas purification system as well as a further data cloud on the Internet (into which, for example, a manufacturer of the exhaust gas purification system may also enter data).

The system data stored in the data cloud were at least partially received beforehand by the data cloud from the exhaust gas purification system. For example, the exhaust gas purification system may transmit the system data continuously, periodically (e.g., hourly or daily) or in an event-triggered manner via the Internet to the data cloud. In some embodiments, subsets of the system data may have been, for example, entered manually into the data cloud by an operator or manufacturer of the exhaust gas purification system. Likewise, subsets of the system data may also have been received by the data cloud from other systems (e.g., exhaust gas purification system(s) similar or identical to the monitored exhaust gas purification system; industrial systems and/or further exhaust gas purification systems coupled to the monitored exhaust gas purification system).

The system data relate to at least measurement data of at least one sensor of the exhaust gas purification system and/or data about at least one adjustable parameter of the exhaust gas purification system. The system data may in general include all data recorded by the exhaust gas purification system or data derived from the recorded data by the exhaust gas purification system. Likewise, the system data may include, for example, measurement data of at least one sensor of the industrial system(s), the exhaust gas or exhaust air of which is purified by the exhaust gas purification system. Measurement data from sensors of the industrial system(s) are sometimes forwarded at least in part to the connected exhaust gas purification systems so that these are also present at the exhaust gas purification system and may be understood as data recorded by the exhaust gas purification system. For example, the system data relating to the measurement data of the at least one sensor may be the actual measurement data of the sensor or data derived therefrom by the exhaust gas purification system. Accordingly, the system data relating to the at least one adjustable parameter of the exhaust gas purification system may be, e.g., a value of the adjustable parameter or data derived therefrom by the exhaust gas purification system. In some embodiments, the system data stored in the data cloud may be identical to the data received from the exhaust gas purification system. In other words: In some embodiments, the system data in the data cloud are not further processed before they are fed into the inventive method. In alternative embodiments, the data received from the exhaust gas purification system may also be modified by the data cloud before being stored. For example, the data format of received system data may be changed before being stored. In order to save memory space, data received continuously by the data cloud (e.g., a parameter of the exhaust gas purification system) may only be stored if the data change (e.g., parameters of the exhaust gas purification system change), or only information relating to the change of the data may be stored (e.g., the value by which a parameter of the exhaust gas purification system has changed), for example.

Furthermore, the system data may also include supplementary data from other sources (see examples above). For example, the supplementary data may be data characterizing the exhaust gas purification system, data from an operating history of the exhaust gas purification system, data from identical or similar exhaust gas purification systems—in particular also data on or about their operating history and/or operating states, data from systems in the same emission line (e.g., for a cascade of various exhaust gas purification systems at the end of at least one production process), etc.

In other words: the system data of the exhaust gas purification system stored in the data cloud may include unprocessed raw data of the exhaust gas purification system in particular, data pre-processed by the exhaust gas purification system, supplementary data from further sources or a combination thereof.

The type as well as the number of the quantities measured at the exhaust gas purification system may vary depending on the type of exhaust gas purification system. For example, other quantities may be measured at an exhaust gas purification system that operates according to the TNV principle than at an exhaust gas purification system that uses electromechanical methods for exhaust gas purification. Some possible measures are listed below, wherein it must be considered that these are chosen merely as examples and that other and/or further (physical) quantities may also be measured at the exhaust gas purification system according to embodiments of the invention.

A sensor of the exhaust gas purification system may, for example, measure a temperature such as a temperature of a combustion chamber or an exhaust gas stream or exhaust air stream. It is also possible to measure, for example, a position of a flap of the exhaust gas purification system. For example, an open or closed position or a relative opening angle of the flap may be measured binarily. Likewise, for example, a volume flow of an exhaust gas stream or exhaust air stream, a pressure of an exhaust gas stream or exhaust air stream or an instantaneous frequency of a frequency converter of a fan driving an exhaust gas stream or exhaust air stream may be measured. Likewise, one or more mass flows may be measured at the system. For example, the mass flow of the natural gas used for oxidation may be measured via a gas meter. In some embodiments, the mass flow of compressed air or also the mass flow of a heat transfer medium (e.g., water, pressurized water, thermal oil or molten salt) may be measured, for example. Likewise, concentrations of one or more substances may be measured, for example. The concentration measurement may, for example, be carried out directly by means of a flame ionization detector or via an explosimeter measuring a concentration of potentially explosive gases. For example, the concentration of carbon dioxide (CO₂) in an exhaust gas stream to be purified and/or a purified exhaust gas stream may be measured. In some embodiments, the specific calorific value of a solvent contained in an exhaust gas stream to be purified may also be measured, for example. In exhaust gas purification systems using filter methods, for example, particle numbers may be measured in an exhaust gas stream to be purified and/or a purified exhaust gas stream. Likewise, on/off information describing the on or off state of an element of the exhaust gas purification system may be measured. For example, it may be measured at an exhaust gas purification system working according to the RTO principle, whether natural gas is injected into the combustion chamber or not. On/off information may, for example, be collected or stored as digital values or binary values (e.g., 0/1) in order to save memory space.

Likewise, the data about the at least one adjustable parameter of the exhaust gas purification system may vary depending on the type of exhaust gas purification system. For example, the data about the at least one adjustable parameter of the exhaust gas purification system may include information about an operation mode in which the exhaust gas purification system is operated at the moment or was operated in the past. The data about the at least one adjustable parameter of the exhaust gas purification system may also include, for example, target positions for a flap of the exhaust gas purification system, target temperatures in a combustion chamber of the exhaust gas purification system, target temperatures of an (e.g., purified) exhaust gas stream or exhaust air stream, target volume flows of an (e.g., purified) exhaust gas stream or exhaust air stream or also deviations of an actual value from a target value of the adjustable parameter. The examples recited above for the adjustable parameter of an exhaust gas purification system are again chosen merely as examples. Other and/or further adjustable parameters of the exhaust gas purification system may also be recorded according to embodiments of the invention.

In addition to retrieving the system data of the exhaust gas purification system from the data cloud, the inventive method further comprises determining at least one quantity characterizing the exhaust gas purification system based on the retrieved system data. The quantity characterizing the exhaust gas purification system describes an operating characteristic of the exhaust gas purification system. The quantity characterizing the exhaust gas purification system may describe both an instantaneous characteristic of the exhaust gas purification system and a characteristic of the exhaust gas purification system over a longer period of time. The quantity characterizing the exhaust gas purification system may be varied and depend, for example, on the type of exhaust gas purification system. It is to be understood that, according to embodiments, not only a single quantity characterizing the exhaust gas purification system may be determined from the system data, but (in parallel or sequentially) a variety of quantities characterizing the exhaust gas purification system may also be determined. For example, several of the quantities characterizing the exhaust gas purification system described below may be determined in parallel or sequentially according to the inventive method.

The quantity characterizing the exhaust gas purification system may be, for example, a status of the exhaust gas purification system. For example, it may be determined from the system data, whether the actual operation of the system deviates from a given or predetermined target operation. The quantity characterizing the exhaust gas purification system may also be, for example, an energy index (e.g., energy consumption, fuel consumption, etc.) or a material index (e.g., pollutant balance, amount of exhaust gas processed, etc.) describing an instantaneous operation of the exhaust gas purification system or the operation of the exhaust gas purification system over a longer period of time. The quantity characterizing the exhaust gas purification system may also describe a trend or a development of the exhaust gas purification system (e.g., an operating parameter or measurement parameter of the exhaust gas purification system changes over a longer period of time).

The automated determination of the quantity characterizing the exhaust gas purification system according to the inventive computer-implemented method may enable an automated, time-efficient and thus less extensive monitoring of the exhaust gas purification system. Calculation routines or algorithms only need to be stored once and may then evaluate the system data stored centrally in the data cloud. A manual evaluation of the system data by suitably qualified personnel may therefore be omitted. The monitoring of the exhaust gas purification system may therefore also be carried out more cost-effectively. For example, one or more quantities characterizing the exhaust gas purification system may be identified for a user or operator of the exhaust gas purification system and automatically determined or derived from the system data by means of the inventive computer-implemented method. In addition to quantities that are conditioned, for example, by the type of exhaust gas purification system (e.g., RTO or TNV), quantities of individual interest to the user or operator may also be automatically determined by means of the inventive computer-implemented method, for example.

Due to the storage of the system data in the data cloud, the system data may be accessed from any location and at any time. The evaluation of the system data or the determination of the quantity characterizing the exhaust gas purification system may thus take place, for example, in the data cloud itself or in a data processing system coupled to the data cloud. For example, an operator or a manufacturer of the exhaust gas purification system may maintain a data processing system to retrieve the system data from the data cloud and evaluate it locally in the data processing system.

In comparison to conventional data collection approaches for exhaust gas purification systems, the data storage in the data cloud not only allows access to current system data, but also to system data of any point in time or period of time. Accordingly, it is not only possible to characterize the exhaust gas purification system based on current system data, but it is substantially possible to evaluate any points in time or periods of time. Due to the storage of the system data in the data cloud, redundant data storage also takes place, so that the risk of data loss is reduced compared to conventional data collection approaches for exhaust gas purification systems.

The inventive computer-implemented method may enable an operator or manufacturer of the exhaust gas purification system to monitor the operation of the exhaust gas purification system more easily via a central means and to track the functioning of the exhaust gas purification system.

According to some embodiments, the computer-implemented method includes, in addition, providing information about the quantity characterizing the exhaust gas purification system for retrieval by an application executed on a terminal device of a user. In this way, the user may easily retrieve the information about the quantity characterizing the exhaust gas purification system and monitor or trace the operation of the exhaust gas purification system via the application. The terminal device of the user may be, for example, a mobile terminal device, such as a smartphone, a tablet computer, or a laptop computer, or a stationary terminal device, such as a computer. The application may be, for example, an application specifically provided for monitoring the exhaust gas purification system. Alternatively, the application may also be a universal application (e.g., an Internet browser). The information about the quantity characterizing the exhaust gas purification system may be provided, for example, as a value or series of values retrievable via the application or as a graphic retrievable via the application. Accordingly, the information about the quantity characterizing the exhaust gas purification system may be provided in a format that is easy to understand for the user.

In some embodiments, the information about the quantity characterizing the exhaust gas purification system is provided on a web site with access restricted to a predetermined user group. The provision of the information about the quantity characterizing the exhaust gas purification system on a web site enables access at any time and place to the quantity characterizing the exhaust gas purification system by the user, and thus a flexible monitoring of the exhaust gas purification system. For example, the output of the information via a web site may also enable the user to create individual notifications using appropriate configuration options on the web site. In addition, the access restriction enables the system monitoring to be secured against access by unauthorized third parties. Access may be restricted, for example, by a password, a security certificate, or local access restrictions.

In addition to the system data, the quantity characterizing the exhaust gas purification system may also be stored in the data cloud according to some embodiments. In other words: the computer-implemented method may further include storing of information about the quantity characterizing the exhaust gas purification system in the data cloud. In this way, the information about the quantity characterizing the exhaust gas purification system may also be stored redundantly in the data cloud, such as to enable access to the information about the quantity characterizing the exhaust gas purification system flexible as to time and place with a minimized risk of data loss.

In some embodiments, the determination of the at least one quantity characterizing the exhaust gas purification system is carried out continuously. This means that the quantity characterizing the exhaust gas purification system is determined steadily (constantly) by the computer-implemented method. In this way, a user may be permanently provided with current values for the characterizing quantity for retrieval. In addition, the continuous determination of the characterizing quantity enables determining temporal courses or temporal changes of the characterizing quantity, which in turn may themselves characterize the exhaust gas purification system or the operating behavior thereof.

In alternative embodiments, the quantity characterizing the exhaust gas purification system is determined discontinuously—for example, periodically or as a result of the occurrence or detection of the occurrence of a predetermined event. If, for example, a specific quantity characterizing the exhaust gas purification system is required only once a year to prepare a legally required report, it may be sufficient to determine this quantity only once a year from the system data. In this way, calculation effort may be saved for unnecessary determinations (e.g., calculations) of the quantity characterizing the exhaust gas purification system.

According to some embodiments, the quantity characterizing the exhaust gas purification system is a quantity directly measurable at the exhaust gas purification system, but which (in reality) is not measured at the exhaust gas purification system. The term “directly measurable” is to be understood in such a way in this context that the quantity considered would (theoretically) be directly measurable at the respective element of the exhaust gas purification system via a suitably configured sensor if a suitable sensor was installed at the exhaust gas purification system or a sensor installed at the exhaust gas purification system was, for example, functional or calibrated. For example, the volume flow of exhaust gas coming into the exhaust gas purification system could be measured directly via a volume flow sensor at the inlet of the exhaust gas purification system. The direct recording of a quantity characterizing the exhaust gas purification system by means of a dedicated sensor at the exhaust gas purification system may be very cost-intensive due to the sometimes high acquisition costs for the sensor. In many cases, it is possible to derive a quantity characterizing the exhaust gas purification system from other measurement data that are recorded as well. For example, a quantity characterizing the exhaust gas purification system may be derived from other recorded measurement data by means of thermodynamic correlations or oxidation calculations. In the above example, the volume flow may be calculated or determined from the difference of pressures measured along the exhaust gas stream, for example. The inventive method may thus determine quantities characterizing the exhaust gas purification system without direct measurement and without the use of sometimes high-priced sensors. This is made clear once again in the following example.

A quantity of interest may, for example, be the efficiency of the exhaust gas purification system, which indicates which portion of one or more pollutants fed into the exhaust gas purification system is removed from the exhaust gas stream or exhaust air stream by the exhaust gas purification system. The efficiency η_(Pollut) may be defined as follows:

$\begin{matrix} {\eta_{Po{llut}} = {\frac{c_{Input} - c_{output}}{c_{Input}} = {1 - \frac{c_{{Outp}ut}}{c_{{Inpu}t}}}}} & (1) \end{matrix}$

In the mathematical expression (1) c_(input) denotes the concentration of the at least one pollutant in the exhaust gas stream to be purified which comes into the exhaust gas purification system and c_(Output) the concentration of the at least one pollutant in the purified exhaust gas stream which is discharged from the exhaust gas purification system. The two pollutant concentrations characterizing the exhaust gas purification system could be measured continuously and directly (immediately) in the exhaust gas stream to be purified or in the purified exhaust gas stream by means of suitable sensors. However, appropriate sensors are high-priced, which is why it is desirable to install as few such sensors as possible or no such sensors in the exhaust gas purification system. Instead of the concentration of the pollutant in the exhaust gas streams, e.g., the respective number of pollutant particles in the exhaust gas stream to be purified and the purified exhaust gas stream may alternatively be measured. The level of particle separation and, hence, the efficiency η_(Pollut) of the exhaust gas purification system may be determined analogously to the above mathematical expression (1) based on the number of particles in the exhaust gas stream to be purified and the number of particles in the purified exhaust gas stream.

In the present case, the concentration of the at least one pollutant in the exhaust gas stream to be purified that is fed into the exhaust gas purification system may be determined, according to the invention, from the system data as the quantity characterizing the exhaust gas purification system. For this purpose, various approaches are possible, wherein three approaches are described below merely as examples.

For example, the pollutant sensor for direct measurement of the concentration of the at least one pollutant in the exhaust gas stream to be purified may be omitted and the concentration may be determined from measurement values of an already present carbon dioxide sensor of the exhaust gas purification system, which measures a carbon dioxide concentration in a purified exhaust gas stream, which is transmitted from the exhaust gas purification system. The carbon dioxide concentration in the purified exhaust gas stream corresponds to the sum of the carbon dioxide comprised in the exhaust gas stream to be purified and to the carbon dioxide generated during the conversion of the pollutant (e.g., by TNV). The concentration of the at least one pollutant (e.g., measured as organically bound carbon by means of a flame ionization detector) correlates with the amount converted into carbon dioxide.

When determining the concentration of the at least one pollutant in the exhaust gas stream to be purified, it may optionally also be taken into account that, for example, the oxidation of the exhaust gas stream to be purified results in different volume flows for the exhaust gas stream coming into the exhaust gas purification system or the exhaust gas stream discharged from the exhaust gas purification system. Such dilution effects may be taken into account, e.g., via one or more correction terms (of the same or different order).

Alternatively, the concentration of the at least one pollutant in the exhaust gas stream to be purified may also be determined, for example, from measurement values of an explosimeter of the exhaust gas purification system which measures a concentration of potentially explosive gases in the exhaust gas stream to be purified. Such concentration meters, also referred to as LEL (lower explosive limit) sensors, are partly already present at the exhaust gas purification system for safety reasons (e.g., in the collector at the inlet of the exhaust gas purification system). The concentration of the at least one pollutant in the exhaust gas stream to be purified may then be determined from the measurement values of the explosimeter, taking into account the calibration of the explosimeter.

Likewise, the concentration of the at least one pollutant in the exhaust gas stream to be purified may also be determined, for example, from measurement values of a mass flow sensor of the exhaust gas purification system measuring a mass flow of a fuel used for a thermal oxidation of the exhaust gas stream to be purified. A higher concentration of the at least one pollutant in the exhaust gas stream to be purified correlates with a lower amount of fuel needed, since the fuel is substituted by the increased pollutant rate in the exhaust gas stream to be purified.

The concentration of the at least one pollutant in the purified exhaust gas stream may, for example, be measured once when putting the machine into service or during periodically recurring measurements in line with legal provisions (e.g., in accordance with § 28 of the Federal Immission Control Act (Bundes-Immissionsschutzgesetz) in Germany) in a representative operation mode of the exhaust gas purification system and assumed to be substantially constant. The measurement value for the concentration of the at least one pollutant in the purified exhaust gas stream may be, e.g., automatically sent to the data cloud by the exhaust gas purification system or manually entered into the data cloud by an operator of the exhaust gas purification system, for example.

In some embodiments, the inventive computer-implemented method may further include determining a pollutant balance of the exhaust gas purification system for a predetermined period of time based on the determined concentration of the at least one pollutant in the exhaust gas stream to be purified. The pollutant balance of the exhaust gas purification system balances the amount of the at least one pollutant fed into the exhaust gas purification system and the amounts of the at least one pollutant discharged from the exhaust gas purification system. In other words: The pollutant balance of the exhaust gas purification system indicates which mass flow of the at least one pollutant was disposed of by the exhaust gas purification system and which mass flow of the at least one pollutant was discharged into the atmosphere as a purified gas emission in the predetermined period of time. The amount of pollutants fed into the exhaust gas purification system in the predetermined period of time results from the data of the volume flow of the exhaust gas fed into the exhaust gas purification system and the associated concentration of the at least one pollutant.

The pollutant balance may further be based on an individual measurement value of the concentration of the at least one pollutant in the purified exhaust gas stream discharged from the exhaust gas purification system comprised in the retrieved system data. As stated above, the concentration of the at least one pollutant in the purified exhaust gas stream may be assumed to be substantially constant so that, for example, this value may be balanced via the amount of exhaust gas fed into the exhaust gas purification system in the predetermined period of time in order to determine the amount of pollutants emitted by the exhaust gas purification system into the atmosphere in the predetermined period of time. In other words: the individual measurement value may be regarded as a reference measurement value that is measured only once.

With reference to the embodiment above, the efficiency of the exhaust gas purification system may also be determined via the amount of exhaust gas fed into the exhaust gas purification system in the predetermined period of time in order to determine the amount of pollutants detoxified in the exhaust gas purification system in the predetermined period of time.

The pollutant balancing with respect to the exhaust gas purification system may enable a user to monitor the proper functioning of the exhaust gas purification system. In addition, pollutant balancing with regard to the exhaust gas purification system may make it easier for the user to comply with legal regulations and reporting obligations.

For example, the at least one pollutant may be one or more organic or inorganic solvents. In Germany, users of solvents are obliged to prepare an annual solvent balance in accordance with the Federal Immission Control Act. In the balance, the user lists the solvent masses used and their fate (recovery, remaining in products, disposal, fugitive emissions).

For example, the user demonstrates by means of his inventory management that 500 tonnes of ethyl acetate per year are used as solvent for printing a flexible packaging. Furthermore, it may be determined via measurements and/or estimations that the exhaust air contains 4 g of ethyl acetate per m³ before the exhaust gas purification. The exhaust air purification system is operated, for example, at 3,500 h per year with a volume flow of 30,000 m³/h (corresponds to 420 t/a). The exhaust gas purification system achieves a purification to 20 mg/m³ (e.g., known from individual measurement). This corresponds to about 2 t/a of solvent emissions into the atmosphere. This results in a balance sheet deficit of 80 t/a. The user may exclude (e.g., postulate for the example case) that solvent remains in the product. Furthermore, in this example, no solvents are recovered from the exhaust air, so that the rest leaves production as so-called “fugitive emissions from undocumented sources” (e.g., hall ventilation is to be named here).

The solvents fed into the exhaust air purification system generally do not represent a constant mass flow. The concentration in the exhaust air as well as the exhaust air volume flow vary in part considerably.

A continuous recording of the concentrations before and after the exhaust gas purification system, as it would be necessary for an accurate balancing, is often not given due to the high costs associated therewith. While the purified gas values tend to fluctuate less (see above), the values of the solvent concentration in the exhaust gas stream to be purified and the exhaust gas volume flow represent a considerable mathematical (balance sheet) uncertainty. By means of the indirect determination of the concentration of the at least one pollutant in the exhaust gas stream to be purified and the volume flow from the system data of the exhaust gas purification system described above, the quantities required for the balancing may be determined with little effort and automatically. This results in a significant simplification as well as time and thus cost savings for the user.

According to some embodiments, the quantity characterizing the exhaust gas purification system may also be, for example, an energy consumption of the exhaust gas purification system for a predetermined period of time and/or a predetermined operation mode of the exhaust gas purification system. Accordingly, the energy consumption of the exhaust gas purification system may be recorded by means of the inventive computer-implemented method. In this connection, the energy consumption of the exhaust gas purification system may be both the total energy consumption of the exhaust gas purification system and an energy consumption related to a specific energy source or a specific energy type. For example, the electrical energy consumed by the exhaust gas purification system or the energy consumed by the exhaust gas purification system in the form of fuels (e.g., natural gas or biogas) may be determined from the system data. The determined energy consumptions may, for example, be analyzed with regard to energy saving potentials and thus be used to increase the energy efficiency of the exhaust gas purification system. The automatically determined energy consumption may also make it easier to comply with reporting obligations (e.g., DIN EN ISO 50001), since an extensive and labor-intensive manual data evaluation by qualified personnel may substantially be omitted. The energy consumptions may also be used for conclusions about a proper operation of the exhaust gas purification system.

The energy consumption may be derived from various quantities measured at the exhaust gas purification system. For example, the amount of fuel consumed (e.g., natural gas), a volume flow of the exhaust gas stream to be purified (e.g., incl. solvents), the electrical energy consumed to drive fans and pumps or the electrical energy consumed to generate or conduct compressed air may be measured and the energy consumption of the exhaust gas purification system may be determined therefrom. Exhaust gas losses, process heat generated by the exhaust gas purification system or transmission heat losses may also be taken into account, for example. In this connection, it should be noted again that the above-mentioned quantities are chosen merely as examples and other or more or less quantities may also be considered.

According to the invention, for a predetermined period of time and/or a predetermined operation mode of the exhaust gas purification system, the amount of energy required for the purification or treatment of a predetermined volume of exhaust gas or exhaust air may be determined, for example. If the amount of exhaust gas or exhaust air generated during the manufacturing of a product is known, the amount of energy required for the manufacturing of a specific amount or a specific volume of the product may also be determined for the exhaust gas purification or exhaust air purification. For example, if the exhaust gas purification system provides process heat, the amount of energy required to generate or provide a predetermined amount of process heat may also be determined. An operator or manufacturer of the exhaust gas purification system may thus be enabled to characterize the exhaust gas purification system in a variety of ways with regard to the consumption of energy.

In some embodiments of the inventive method, the determined energy consumption of the exhaust gas purification system may also be compared with one or more planned energy consumptions. In this way, an actual consumption may be compared with a target consumption, for example. In the same way, it may also be shown, for example, to an operator of the exhaust gas purification system how much of the energy consumed was consumed for the basic operation of the exhaust gas purification system (e.g., system ready for operation but idling) and how much energy was consumed depending on the load. In this way, for example, energy consumptions may be compared between several years—irrespective of the production tonnage, i.e., the actual amount of exhaust gas or exhaust air treated.

When determining the energy consumption, it is in turn possible to use quantities derived from the system data instead of directly measured quantities. For example, determining the energy consumption may include deriving, from at least a part of the retrieved system data, a quantity directly measurable at the exhaust gas purification system that is not measured at the exhaust gas purification system. For example, a volume flow may be derived from existing pressure measurements according to the principles described above instead of being measured directly at the exhaust gas purification system. Determining the energy consumption then includes a corresponding determination of the energy consumption based on the quantity derived. As already mentioned above, the energy consumption may thus be determined without the use of sometimes high-priced sensors. The monitoring of the exhaust gas purification system with regard to its energy consumption may thus be carried out more cost-effectively.

In addition to the energy consumption, an energy balance of the exhaust gas purification system may also be determined from the system data according to some embodiments, which indicates how much energy was fed into the exhaust gas purification system and how much energy was released again from the exhaust gas purification system.

In some embodiments, the quantity characterizing the exhaust gas purification system may also be, for example, an amount of process heat that is generated or may be generated by the exhaust gas purification system in a predetermined period of time. The determination of the amount of process heat that is generated or may be generated may enable an operator of the exhaust gas purification system to be able to better classify the exhaust gas purification system with regard to his energy management concept. The exhaust gas purification system may also be monitored to determine whether the planned amounts of process heat were actually provided by the exhaust gas purification system.

The amount of process heat that is generated or may be generated may be derived from various quantities measured at the exhaust gas purification system. Some examples are described in more detail below.

The amount of process heat that may be generated may be determined, e.g., for an exhaust gas purification system for RTO with hot bypass in above-autothermal operation (without heat use), from the measured position of the hot gas flap (as an estimate for the volume flow of the purified exhaust gas) and the measured or given temperature (adjustable parameter) of the heat transfer medium.

With the same approach, the amount of process heat actually generated may also be determined or estimated for an exhaust gas purification system that operates according to the RTO principle with heat use in above-autothermal operation. Alternatively, the process heat actually generated may also be determined, for example, from the measured flow rate of the heat transfer medium through the heat transfer apparatus and the associated temperature difference (between outlet and inlet of the heat transfer medium into/out of the heat transfer apparatus).

The amount of heat recovered from the exhaust gas or the exhaust air that could be reused during operation may thus be presented to an operator of the exhaust gas purification system. For example, it is further possible to determine the amount of process heat generated and the amount of solvents used for this in above-autothermal operation of the exhaust gas purification system. The operator of the exhaust gas purification system may thus better characterize the exhaust gas purification system and integrate it into his energy management concept. The operator of the exhaust gas purification system may also verify whether the exhaust gas purification system generates process heat in accordance with the requirements (e.g., in accordance with the design).

The generation of process heat may be energetically advantageous in the exhaust gas purification system irrespective of the operation mode, for example, even if natural gas is used in the combustion chamber at the same time. In this context, the amount of solvent that was consumed up to the autothermal operating point of the exhaust gas purification system and the amount of solvent that may be additionally used in the exhaust gas stream or exhaust air stream to be purified may be taken into account, for example. An operator of the exhaust gas purification system may thus see from the balance the amount of process heat generated and the amount of solvent and fuel used for this. The operator of the exhaust gas purification system may thus better characterize the exhaust gas purification system and integrate it into his energy management concept. The operator of the exhaust gas purification system may also verify whether the exhaust gas purification system generates process heat in accordance with the requirements (e.g., in accordance with the design).

When determining the amount of process heat that is generated or may be generated, it is in turn possible to use quantities derived from the system data instead of directly measured quantities. For example, determining the amount of process heat that is generated or may be generated may include deriving a quantity directly measurable at the exhaust gas purification system, which is not measured at the exhaust gas purification system, from at least a part of the retrieved system data. For example, a volume flow may be derived from existing pressure measurements according to the principles described above instead of being measured directly at the exhaust gas purification system. Determining the amount of process heat that is generated or may be generated then accordingly comprises determining the amount of process heat that is generated or may be generated based on the quantity derived. As already mentioned above, the amount of process heat that is generated or may be generated may thereby be determined without the use of sometimes high-priced sensors.

In some embodiments, the quantity characterizing the exhaust gas purification system may be, for example, an amount of fuel consumed in a predetermined period of time and/or in a predetermined operation mode. In this way, the consumption of operating materials by the exhaust gas purification system may be easily monitored. For example, the amount of natural gas consumed at an exhaust gas purification system operating according to the TNV principle, or an amount of injected urea in a DeNOx stage, or an amount of acid or base used in a scrubber may be monitored.

As already indicated above, exhaust gas purification systems may also comprise one or more separation devices (e.g., cyclone separator, filtering device, wet or dry electrostatic precipitator) for separating at least one pollutant contained in the exhaust gas stream to be purified. Accordingly, the quantity characterizing the exhaust gas purification system may be a quantity characterizing the separation process in the exhaust gas purification system, according to embodiments. The quantity characterizing the exhaust gas purification system may be, for example, an electrical energy requirement of an electrostatic precipitator depending on properties of the exhaust gas stream to be purified (i.e., raw gas properties) or an energy used for the electrostatic precipitator depending on an efficiency of the electrostatic precipitator. The quantity characterizing the separation process in the exhaust gas purification system may be determined, for example, from measurement data of at least one sensor of the exhaust gas purification system which measures a property of the exhaust gas stream to be purified, a sensor of the exhaust gas purification system which measures a property of the purified exhaust gas stream, and/or control data for the at least one separation device (e.g. data about an adjustable parameter of the separation device or an operating parameter of the separation device).

Likewise or alternatively, exhaust gas purification systems may also comprise one or more concentration devices for increasing a concentration of at least one pollutant contained in the exhaust gas stream to be purified. In some embodiments, the quantity characterizing the exhaust gas purification system may accordingly be a quantity characterizing the concentration process in the exhaust gas purification system. The quantity characterizing the exhaust gas purification system may also be, for example, a concentration of the pollutant in the exhaust gas stream to be purified or in the purified exhaust gas stream depending on the rotational speed of an adsorption wheel of the exhaust gas purification system.

Also, exhaust gas purification systems (e.g., together with at least one concentration device) may comprise one or more condensation devices for condensing at least one pollutant contained (and possibly concentrated) in the exhaust gas stream to be purified. In some embodiments, the quantity characterizing the exhaust gas purification system may accordingly be a quantity characterizing the condensation process. The quantity characterizing the condensation process may be, for example, an electrical energy input per amount of pollutant recovered (e.g., a solvent) or a characteristic (e.g., temperature) of one of several condensation stages of the condensation device depending on a composition of the condensate obtained.

As already indicated in the examples discussed above, further characteristics or indexes may also be derived from the quantities characterizing the exhaust gas purification system. In some embodiments, the inventive computer-implemented method thus further includes determining a characteristic of the exhaust gas purification system based on the quantity characterizing the exhaust gas purification system.

In some embodiments, the inventive computer-implemented method further includes issuing a message to at least one terminal device of a user if the quantity characterizing the exhaust gas purification system is outside a predetermined value range. Accordingly, the user may be informed about an operation of the exhaust gas purification system outside the given specifications so that the user may react accordingly. For example, a message or an e-mail may be sent to the at least one terminal device of the user. Accordingly, the inventive computer-implemented method may also include outputting a message to a terminal device of a user if the measurement data of the at least one sensor of the exhaust gas purification system included in the system data are outside a predetermined value range.

According to the invention, the computer-implemented method may also be used to monitor several exhaust gas purification systems coupled to the data cloud. For example, several exhaust gas purification systems may be compared with each other. Accordingly, the inventive computer-implemented method comprises, according to some embodiments, a retrieval of system data of a further exhaust gas purification system from the data cloud. The system data of all exhaust gas purification systems are the same with regard to their type and structure, respectively. According to the principles described above, the method further includes determining the characterizing quantity for the further exhaust gas purification system based on the retrieved system data of the further exhaust gas purification system. In addition, the method includes determining comparative information based on the characterizing quantity for the exhaust gas purification system and the characterizing quantity for the further exhaust gas purification system. The comparative information describes a relation or a ratio between the characterizing quantity for the exhaust gas purification system and the characterizing quantity for the further exhaust gas purification system. For example, the comparative information may be a ratio of the characterizing quantity or a graphical comparison of the characterizing quantity for both exhaust gas purification systems. A user may thus be enabled to directly compare the exhaust gas purification systems. From the comparison, the user may, for example, draw conclusions about the performance or necessary changes to the one exhaust gas purification system in comparison to the other exhaust gas purification system. The inventive computer-implemented method may thus enable, for example, an operator or a manufacturer of the exhaust gas purification systems to monitor several exhaust gas purification systems more easily.

Embodiments of the invention further also relate to a non-transitory machine-readable medium on which a program is stored with a program code for executing the inventive method for monitoring at least one exhaust gas purification system when the program is executed on a processor or a programmable hardware component. The non-transitory machine-readable medium may be implemented, for example, as a ROM, PROM, EPROM, EEPROM, FLASH memory or as another magnetic, electrical or optical memory having electronically readable control signals stored thereon, which cooperate or are capable of cooperating with the processor or the programmable hardware component such that the respective method is performed. A programmable hardware component may be formed, e.g., by a processor, a computer processor (CPU=Central Processing Unit), an Application-Specific Integrated Circuit (ASIC), an Integrated Circuit (IC), a System on Chip (SOC), a programmable logics element, a Field Programmable Gate Array comprising a microprocessor (FPGA=Field Programmable Gate Array), a back end or a data cloud. The program code may among others be present as a source code, machine code or byte code or any other intermediate code.

In addition, embodiments of the invention also relate to a program comprising a program code for executing the inventive method for monitoring at least one exhaust gas purification system when the program is executed on a processor or a programmable hardware component.

According to a further aspect, the invention further relates to a data processing system for monitoring the state of at least one exhaust gas purification system (e.g., for purifying an exhaust gas stream of an industrial system or an industrial process). The data processing system comprises at least one processor configured to retrieve system data of the exhaust gas purification system from a data cloud. The system data stored in the data cloud were at least partially received beforehand by the data cloud from the exhaust gas purification system. The system data relate to at least measurement data of at least one sensor of the exhaust gas purification system and/or data about at least one adjustable parameter of the exhaust gas purification system. In addition, the system data may include one or more of the above-mentioned further subsets of system data. Additionally, the at least one processor is configured to determine a quantity characterizing the exhaust gas purification system based on the retrieved system data.

As already described above in connection with the inventive computer-implemented method, the inventive data processing system may also make it possible to monitor the operation of the exhaust gas purification system simply and centrally and to track the function of the exhaust gas purification system.

For example, the data processing system may be part of the data cloud and the at least one processor may thus be a virtual or physical processor of the data cloud. Accordingly, the entire monitoring of the exhaust gas purification system may take place in the data cloud, so that a local provision of an accordingly powerful data processing system by, e.g., an operator or a manufacturer of the exhaust gas purification system is unnecessary. Instead, the system monitoring in the data cloud may be easily accessed as a service. In other words: The steps of the inventive computer-implemented method described herein may all be executed in the data cloud or via the data cloud.

In some embodiments, the data processing system may alternatively also be, for example, a computer, a server, a server system or a back end that may access the data cloud and may be operated, for example, by an operator or a manufacturer of the exhaust gas purification system. According to further embodiments, the data processing system may further be a terminal device of a user which may access the data cloud.

In one aspect, the invention additionally also applies to an exhaust gas purification system for purifying an exhaust gas stream to be purified of an industrial system or an industrial process (e.g., of the chemical or pharmaceutical industry). The inventive exhaust gas purification system comprises at least one inlet for introducing the exhaust gas stream to be purified into the exhaust gas purification system and one outlet for transmitting a purified exhaust gas stream from the exhaust gas purification system. Furthermore, the inventive exhaust gas purification system includes a communication interface configured to send system data generated in the exhaust gas purification system to a data cloud, the system data relating to at least measurement data of at least one sensor of the exhaust gas purification system and data about at least one adjustable parameter of the exhaust gas purification system.

The inventive exhaust gas purification system may enable a redundant storing of the system data in the data cloud, so that the risk of data loss is reduced compared to conventional data collection approaches for exhaust gas purification systems. Due to the storage of the system data in the data cloud, the system data may additionally be accessed from any location and at any time.

The communication interface may, for example, be coupled to the data cloud wirelessly or wired via the Internet or a local network. According to embodiments, not only a data transfer from the exhaust gas purification system to the data cloud may take place, but also vice versa. For example, the communication interface may be configured to receive configuration data or software updates for the exhaust gas purification system from the data cloud. Accordingly, a programmable hardware component of the exhaust gas purification system may be configured to process the configuration data or software updates.

The system data of the exhaust gas purification system sent to the data cloud may include unprocessed raw data of the exhaust gas purification system, data pre-processed by the exhaust gas purification system, or a combination thereof.

Depending on the type of treatment (e.g., catalytic, mechanical or catalytic) of the exhaust gas stream to be purified, the exhaust gas purification system may have one or more purifying devices for purifying the exhaust gas stream to be purified (e.g., combustion chamber, filter, etc.). For example, the exhaust gas purification system may comprise a concentration device configured to increase a concentration of at least one pollutant contained in the exhaust gas stream to be purified. Alternatively or additionally, the exhaust gas purification system may comprise a condensation device configured to condense at least one pollutant contained in the exhaust gas stream to be purified. According to embodiments, the exhaust gas purification system may also comprise a separation device configured to separate at least one pollutant contained in the exhaust gas stream to be purified.

Embodiments of the present invention are explained in more detail below with reference to the accompanying figures, in which:

FIG. 1 schematically illustrates a monitoring system for an exhaust gas purification system;

FIG. 2 illustrates an embodiment of a graphical user interface in which various quantities characterizing an exhaust gas purification system are illustrated;

FIG. 3 illustrates an embodiment of operation modes of an exhaust gas purification system;

FIG. 4 illustrates an embodiment of a monitored exhaust gas purification system comprising a separation device; and

FIG. 5 illustrates an embodiment of a monitored exhaust gas purification system comprising a concentration device and a condensation device.

FIG. 1 shows a monitoring system 100 for an exhaust gas purification system 110, which is shown schematically and in a very simplified manner. The exhaust gas purification system 110 comprises an inlet 111 for feeding in an exhaust gas stream 101 to be purified of an industrial system such as a printing machine (not illustrated). Furthermore, the exhaust gas purification system 110 comprises at least one purifying device 114 for purifying the exhaust gas stream 101. For example, the purifying device 114 may purify the exhaust gas stream 101 according to one of the methods described above. The exhaust gas purification system 110 further includes an outlet 112 for transmitting a purified exhaust gas stream 102 from the exhaust gas purification system 110. The exhaust gas purification system 110 also includes at least one sensor 115 to measure a quantity of interest (e.g., a pressure or a concentration of one or more substances) at an element of the exhaust gas purification system 110.

Furthermore, the exhaust gas purification system 110 includes a (wireless or wired) communication interface 113 for connecting the exhaust gas purification system 110 to a data cloud 120. Via the communication interface 113, the exhaust gas purification system 110 may exchange data with the data cloud 120. In particular, the communication interface 113 is configured to send system data generated in the exhaust gas purification system to the data cloud 120. The communication interface 113 may thereby, for example, send the system data continuously, periodically or in an event-triggered manner to the data cloud 120. The system data may include both unprocessed raw data from the exhaust gas purification system 110 and preprocessed data from the exhaust gas purification system 110.

The system data are stored in a storage means 122 of the data cloud 120 (e.g. one or more hard disks), so that the system data may be accessed locally and at any time. Likewise, data loss may be omitted due to the data storage in the data cloud 120. Furthermore, further system data may be entered, for example, manually into the data cloud 120 or received from further systems (e.g. exhaust gas purification system identical or similar to exhaust gas purification system 120—not shown).

Furthermore, the data cloud 120 comprises at least one (virtual or physical) processor 121, which executes the inventive analysis of the system data for monitoring the exhaust gas purification system 110.

For this purpose, the processor 121 is set up to retrieve the system data of the exhaust gas purification system 110 from the storage means 122 of the data cloud 120 and to determine the quantity characterizing the exhaust gas purification system 110 based on the retrieved system data.

Using the quantity characterizing the exhaust gas purification system 110, the current or a past state or the behavior of the system may be described and thus presented to an operator or manufacturer of the exhaust gas purification system 110. Likewise, further characteristics of the exhaust gas purification system 110 may be derived by the processor 121 from the quantity characterizing the exhaust gas purification system 110. The determination of one or more quantities or characteristics characterizing the exhaust gas purification system 110 is carried out according to the principles described above. For example, the processor 121 may be configured to determine an energy consumption or a solvent balance of the exhaust gas purification system 110 according to the principles described above.

The information about the quantity characterizing the exhaust gas purification system 110 may also be stored in the data cloud 120.

Information about the one or more quantities characterizing the exhaust gas purification system may be displayed to a user, for example, via a graphical user interface generated by the processor 121, which the user may access via a terminal device 130 (e.g., a smartphone or a tablet computer). An example of a graphical user interface 200 is shown in FIG. 2. The graphical user interface 200 may, for example, be output via a dedicated application or as a web site on the terminal device 130 of the user.

In the upper right area of the graphical user interface 200, measured temperatures of the exhaust gas purification system 110, such as the temperatures of the exhaust gas stream to be purified, the purified exhaust gas stream, a bed (e.g., lower bed) of the exhaust gas purification system 110 or the combustion chamber, are illustrated as bars or bar charts. Alternatively, other quantities measured at the exhaust gas purification system 110 or the course of a quantity characterizing the exhaust gas purification system 110 derived from the system data may also be illustrated. For example, volume flows (measured directly or determined, for example, from the converter frequency of a fan), flap positions (e.g., hot gas flap), measurement values of LEL sensors or loading states or the state of a fuel injection may be displayed.

Below, a trend display for interesting quantities of the exhaust gas purification system 110 is integrated into the graphical user interface 200. Here, the course of a quantity measured at the exhaust gas purification system 110 or the course of a quantity characterizing the exhaust gas purification system 110 derived from the system data may be illustrated, for example.

In the lower area, an illustration of the operating hours of the exhaust gas purification system 110 for the individual operation modes is further integrated into the graphical user interface 200.

For example, the graphical user interface 200 may be configured individually for a user. Depending on the sensor equipment of the exhaust gas purification system 110, various quantities or parameters characterizing the exhaust gas purification system 110 may thereby be automatically determined or calculated from the system data and displayed to the user. The user may also use these quantities or parameters for required reports, for example. The output of the respective quantities or values for reports is conducted automatically and thus time-efficiently due to the stored calculation routines.

Furthermore, an event list relating to the various possible operation modes of the exhaust gas purification system 110 is illustrated in the upper left area of the graphical user interface 200. The operating states of the exhaust gas purification system 110 may be determined from the analyzed system data of the exhaust gas purification system 110.

An example for a hierarchical structure of a plurality of operation modes of an exhaust gas purification system for RTO is illustrated in FIG. 3. The exhaust gas purification system may generally be in either an off-mode operation 300, an on-mode operation 305, or a failure-mode 310.

While the exhaust gas purification system is in the on-mode operation 305, the exhaust gas purification system may be in a start-up-mode operation 315, in which the exhaust gas purification system heats up, or in a shutdown-mode operation 325, in which the exhaust gas purification system is switched off “normally” and flushed with fresh air (mode 326) or cooled after a failure (mode 327). During the on-mode operation 305, the exhaust gas purification system may also be in a purifying-mode operation 330, in which the exhaust gas purification system is purified, or a regular-mode operation 320, in which the exhaust gas stream is purified.

In the regular-mode operation 320, the exhaust gas purification system may be in a below-autothermal-mode operation 335, in which the exhaust gas is purified by means of RTO with an injection of a fuel to ensure a minimum combustion chamber temperature. Alternatively, the exhaust gas purification system may be in a stand-by-mode in the below-autothermal-mode operation 335, in which the combustion chamber temperature is maintained above a minimum temperature with minimum air supply.

Likewise, the exhaust gas purification system may be in an autothermal-mode operation 340 in the regular-mode operation 320, in which the exhaust gas is purified by means of RTO without the addition of further fuel, but hot gas cannot yet be dissipated for process heat recovery.

In the above-autothermal-mode operation 345, the exhaust gas is purified by means of RTO without adding further fuel and the hot gas flap in the exhaust gas purification system is set such as to dissipate the hot gas via a hot bypass for process heat recovery.

In the forced-cooling-mode operation 350, the exhaust gas is purified by means of RTO without the addition of further fuels and the maximum amount of hot gas is dissipated for process heat recovery. In order to protect the exhaust gas purification system from too high oxidation temperatures due to the exothermic nature of the solvent in the exhaust gas, cold air is additionally fed into the combustion chamber.

In the intentional-extraction-mode operation 355, the exhaust gas is purified by means of RTO with an injection of a fuel. At the same time, heat is extracted via the hot bypass of the exhaust gas purification system (controlled by the position of the hot gas flap).

The table below is an overview of the specifications for various adjustable parameters in some of the operation modes mentioned above. The actual values of the parameters may be measured via sensors of the exhaust gas purification system. The measurement values as well as the target values are stored in the data cloud by the exhaust gas purification system and are thus available for the inventive monitoring of the exhaust gas purification system.

combustion chamber natural gas hot mode temperature injection bypass below autothermal less than T1 Yes No autothermal between T1 and T2 No No above autothermal greater than T2 No Yes forced cooling greater than T3 No Yes intentional extraction any Yes Yes

Accordingly, it may be determined from the system data, according to the invention, whether the system behaves according to the specifications for the individual parameters during operation, for example. This allows an automated and efficient monitoring of the exhaust gas purification system.

FIG. 4 shows the monitoring of an exhaust gas purification system 400 with a separation device in the form of an electrostatic precipitator 410 (also referred to as an electrical separator, an electric separator, or an electrostatic separator). It should be noted that the electrostatic precipitator 410 is purely exemplary to illustrate a separation device for separating particles from an exhaust gas stream or exhaust air stream. As an alternative to the electrostatic precipitator 410, a cyclone separator or other filtering device may be used as a separation device, for example.

The exhaust gas purification system 400 comprises an inlet for feeding in an exhaust gas stream 401 to be purified of an industrial system. The electrostatic precipitator 410 is used to purify the exhaust gas stream 401. After purification by the electrostatic precipitator 410, the purified exhaust gas stream 402 is transmitted from the exhaust gas purification system 400 via an outlet.

The electrostatic precipitator 410 is used to separate particles (i.e., a coherent mass of solid or liquid matter) of, for example, a pollutant from the exhaust gas stream 401 to be purified. The functioning of an electrostatic precipitator is known per se and is described, for example, in the guideline VDI 3678 sheet 1 of the Association of German Engineers (VDI; Verein Deutscher Ingenieure). For a better understanding, some aspects of exhaust gas or exhaust air purification by means of electrostatic precipitators are highlighted again below.

The electrostatic precipitator 410 comprises a so-called spray electrode, which generates gas ions in the exhaust gas stream 401 to be purified by means of corona discharge. The pollutant particles contained in the exhaust gas stream 401 to be purified are charged by the ionized gas components and therefore perform a directed movement in the electric field of the electrostatic precipitator 410 towards one or more collecting electrodes (separation electrodes) of the electrostatic precipitator 410. In other words: The charged pollutant particles “migrate” to the collecting electrode(s). The collecting electrode(s) is/are purified and the pollutant particles are thus discharged from the exhaust gas stream.

In a dry electrostatic precipitator 410, the purification of the collecting electrode(s) is accomplished by (e.g., periodically) mechanically tapping the collecting electrode(s) such that the particle layer formed on the collecting electrode(s) is knocked off. In a wet electrostatic precipitator, the separated drops run down quasi-continuously (if applicable, assisted by rinsing with a liquid).

In general, various setups of the electrostatic precipitator 410 are possible. For example, the electrostatic precipitator 410 may be configured as a plate electrostatic precipitator or a tube electrostatic precipitator.

The effectiveness of the separation (i.e., the degree of separation) in the electrostatic precipitator 410 may be adjusted or influenced via a variety of parameters. In addition to the construction or design of the electrostatic precipitator 410 and the regulation of the electric field, for example, a volume flow of the exhaust gas stream 401 to be purified, a composition of the exhaust gas stream 401 to be purified (e.g., depending on the water or acid dew point), a temperature of the exhaust gas stream 401 to be purified, a pressure of the exhaust gas stream 401 to be purified, a particle concentration in the exhaust gas stream 401 to be purified (e.g. a raw gas dust concentration), a specific resistance of the particles (e.g., a specific dust resistance), a grain size distribution of the particles in the exhaust gas stream 401 to be purified, a number of particles in the exhaust gas stream 401 to be purified, a composition of the particles in the exhaust gas stream 401 to be purified (e.g., a dust composition), or a particle concentration to be achieved in the purified exhaust gas stream 402 may influence the effectiveness of the separation.

The raw gas 401 fed into the separator in the form of the electrostatic precipitator 410 is purified as previously described (i.e., the particulate load is reduced), so that the sufficiently purified clean gas 402 may be discharged.

At least one sensor 420 of the exhaust gas purification system 400 may collect (e.g., continuously, discontinuously, or aggregated over time) data regarding the exhaust gas stream 401 to be purified that is relevant for the separation process. Purely by way of example, the sensor 420 may measure, for example, one of the aforementioned parameters of the exhaust gas stream 401 to be purified.

In addition, data regarding the purified exhaust gas stream 402 may be collected by at least one further sensor 430. The second measuring point in the form of the at least one further sensor 430 is optional.

The measurement data of the sensors 420 and 430 are sent from the exhaust gas purification system 400 as system data to the data cloud 440, where they are analyzed according to the invention. If the sensors 420 and 430 determine, for example, particle numbers in the exhaust gas stream 401 to be purified and in the purified exhaust gas stream 402, the efficiency of the electrostatic precipitator 410, for example, may be determined therefrom in the data cloud 440. A user may access the data or analysis (e.g., using the graphical user interface illustrated in FIG. 2) via a terminal device 450.

Other data that may be sent as system data from the exhaust gas purification system 400 to the data cloud 440 is data present in a controller 460 (e.g., a Programmable Logic Controller, PLC) of the exhaust gas purification system 400. Accordingly, this data may also be used for characterization of the separation process in the electrostatic precipitator 410. The further data of the controller 460 may be, for example, a frequency of purification of the collecting electrode(s) (e.g., a frequency of “tapping” in a dry electrostatic precipitator 410), a quantity or mass of separated particles (may be derived or determined from a sensor measurement value, for example), an electrical energy requirement of individual components or aggregated to complete assemblies, a quantity or mass of a cleaning liquid used for purifying the collecting electrode(s) in the case of a wet electrostatic precipitator, a quantity or mass of the separated drops in the case of a wet electrostatic precipitator (may be derived or determined from a sensor measurement value, for example) or a number of flashovers in the electrostatic precipitator. It is to be noted that the aforementioned characteristics are chosen merely as examples and for illustration purposes. According to embodiments, the further data may also display additional, less, or different characteristics.

Some or several of the system data is used to monitor the exhaust gas purification system 400 or analyze the separation process in the electrostatic precipitator 410 after being received by the data cloud 440. For this purpose, one or more quantities characterizing the separation process may be determined by the data cloud 440. For example, an energy used for the electrostatic precipitator 410 may be determined depending on an efficiency of the electrostatic precipitator 410, a tapping interval of the collecting electrode(s) of the electrostatic precipitator 410 may be determined depending on an efficiency of the electrostatic precipitator 410, an electrical energy requirement of the electrostatic precipitator 410 may be determined depending on properties of the exhaust gas stream 401 to be purified, a current flow in the electrostatic precipitator 410 may be determined depending on properties of the exhaust gas stream 401 to be purified (e.g., tracking a temporal change trend) or an adjustment or readjustment for the field strength regulation of the electric field in the electrostatic precipitator 410 may be determined to avoid flashovers. The above-mentioned quantities characterizing the separation process are chosen merely as examples and for illustration purposes. According to embodiments, additional, less or other characterizing quantities may also be determined in the data cloud 440 based on the system data received from the exhaust gas purification system 400.

FIG. 5 illustrates the monitoring of an exhaust gas purification system 500 with solvent recovery. Solvents (e.g., organic solvents such as ethyl acetate, ethanol or isopropanol) are used in various production processes. The solvents sometimes represent a significant resource (costs in part considerably higher than 1 €/kg) so that a solvent recovery may be reasonable for technical and economic reasons.

In this context, an exemplary and very simplified industrial production system 560 is shown in FIG. 5 (e.g., a printing system or a coating system). In addition to the material to be processed (e.g., to be printed or coated), solvent is also fed into the production system 560 (e.g., bound in a printing ink). The solvent input into the production system 560 may be determined, e.g., from measurement values of a sensor 545 (which measures, e.g., the amount of ink in which the solvent is bound). In addition, information regarding the solvents or other relevant system parameters may be collected via one or more further sensors 547 at the production system 560 itself. In a printing system, the solvent is released and transmitted together with the exhaust gas stream 501 upon application of the ink, or at the latest upon drying. For reasons provided by the immission control law, for example, a release of the solvents into the environment is not permissible. Therefore, an exhaust gas purification is carried out by means of the industrial exhaust gas purification system 500.

As illustrated in FIG. 5, the solvent recovery may be carried out by means of various procedural steps. For example, the exhaust gas stream 501 to be purified may first be subjected to a concentration process and subsequently to a desorption process (e.g., by means of water vapor, hot gas or inert gas), before the desorbate generated by this (i.e., the concentrated exhaust gas stream) is fed into a condensation process in order to separate the solvent from the exhaust gas stream by means of condensation. This form of solvent recovery is illustrated in FIG. 5 by the concentration device 520 and the condensation device 510. The exhaust gas stream 501 to be purified is first fed into the concentration device 520 that increases the concentration of at least one pollutant contained in the exhaust gas stream 501 to be purified by means of a concentration method (e.g., adsorption, absorption or membranes). The desorbate 521 generated by this is subsequently fed into a condensation device 510 that condenses the at least one pollutant and thus removes it from the desorbate 521. Accordingly, a purified exhaust gas stream 502 or 502′ is provided by the concentration device 520 and the condensation device 510, respectively.

The concentration may be carried out, for example, by means of a bed adsorber or a concentrator wheel (e.g., with zeolite and/or activated carbon).

Alternatively, the condensation may also be carried out without a previous concentration by the concentration device 520. As indicated in FIG. 5, the exhaust gas stream 501 to be purified may also be directly fed into the condensation device 510. For example, a pollutant of a dryer in the exhaust gas stream 501 to be purified may also be directly condensed by the condensation device 510 (a concentration of the pollutant in the exhaust gas stream 501 to be purified may, for example, be already carried out by a circulation air operation in the dryer itself). Likewise, a condensation of the exhaust gas stream 501 to be purified with a subsequent adsorptive concentration of the residue may be carried out in the condensation device 510 in order to achieve the desired or required maximum pollutant content of the purified exhaust gas stream 502′.

As may be seen from the preceding explanations, the solvent recovery may be carried out using various approaches that may be chosen depending on the process requirements and the type of pollutant or pollutants, for example.

The solvents obtained in the condensation device 510 may be subsequently optionally treated in a solvent treatment device 530 and again fed into the production process or the production system 560. According to embodiments, the treatment may also be omitted. Alternatively, the recovered solvents may also be gathered and further processed externally (i.e., they are not directly fed again into the production process or the production system 560). The purified exhaust gas stream or exhaust gas streams 502 and 502′ may be fed into the environment or again fed into the production process or the production system 560.

Data relating to the individual exhaust gas streams or solvent streams may be collected via one or more sensors 540, 541, 542, 543, 544 or 546. The measurement data of the sensors 540, 541, 542, 543, 544 or 546 are sent as system data to a data cloud 550 by the exhaust gas purification system 500 and analyzed there according to the invention. Furthermore, as indicated in FIG. 5, data of one or more of the sensors 545 and 547 of the industrial production system 560 may also be received by the data cloud 550 and included in the analysis. It is to be noted in this context that the sensors illustrated in FIG. 5 are chosen merely as examples and for illustration purposes. According to embodiments, also more, less or differently placed sensors may be used.

By means of suitable sensors or the recording of suitable parameters or characteristics, an analysis, evaluation or balancing of the entire system or selected sub-processes may be carried out via the data cloud 550. Since the exhaust air purification is aimed at recovery, a direct coupling of the exhaust gas purification system 500 to the production process is given.

Like in the preceding embodiments, sensor information may be evaluated or combined before and/or after a process step or a sub-step (volume flow, pressure, temperature, concentration—e.g., LEL concentration, humidity content, etc.) alone or together with information from the respective process in the data cloud 550 in order to determine one or more characterizing quantities of the exhaust gas purification system 500 and provide it for retrieval by a terminal device 570 of a user.

For the concentration sub-process, a concentration of one or more pollutants in the exhaust gas stream 501 to be purified, in the purified exhaust gas stream 502 or in the desorbate 521, for example, may be determined from the transmitted system data depending on the rotational speed of a adsorption wheel or depending on an inlet temperature of the exhaust gas stream 501 to be purified or the desorption temperature.

In the condensation sub-process, a switching time for a 2-line-condensation may be determined depending on the operating temperature and the gas properties at the inlet of the condensation device. “2-line” means a redundancy of the aggregates in this connection, as one line always freezes during condensation while the other line thaws. Likewise, indexes on individual condensation stages (e.g., temperatures) may be determined as characterizing quantity depending on the condensate composition. A condensation in several stages means in this connection that various enriched fractions are separated separately such as to facilitate a subsequent treatment. According to some embodiments, a respective pumping power for individual condensation levels for monitoring (balancing) individual fractions (e.g., amount of pumped condensate amount depending on input quantities) may also be determined as the characterizing quantity, for example.

Likewise, a balancing of the entire system (production and exhaust gas purification=solvent recovery) may be carried out in the data cloud 550 with regard to the solvent use or a tracking of an enrichment of solvents in a procedural step (in order to avoid the risk of condensation). Likewise, an electrical energy input per unit mass of recovered solvent may be determined as characterizing quantity, for example.

Thus, an automated, efficient and targeted monitoring of the exhaust gas purification system may be carried out. 

1. A computer-implemented method for monitoring at least one exhaust gas purification system for purifying an exhaust gas stream to be purified of an industrial system or an industrial process, the method comprising: retrieving system data of the exhaust gas purification system from a data cloud, wherein the system data stored in the data cloud were at least partially received beforehand by the data cloud from the exhaust gas purification system, and wherein the system data relate to at least measurement data of at least one sensor of the exhaust gas purification system and/or data about at least one adjustable parameter of the exhaust gas purification system; and determining at least one quantity characterizing the exhaust gas purification system based on the retrieved system data.
 2. The computer-implemented method of claim 1, further comprising: providing information about the quantity characterizing the exhaust gas purification system for retrieval by an application executed on a terminal device of a user.
 3. The computer-implemented method of claim 2, wherein the information about the quantity characterizing the exhaust gas purification system is provided on a web site with access restricted to a predetermined user group.
 4. The computer-implemented method of claim 1, further comprising: storing information about the quantity characterizing the exhaust gas purification system in the data cloud.
 5. The computer-implemented method of claim 1, wherein determining the at least one quantity characterizing the exhaust gas purification system is carried out continuously.
 6. The computer-implemented method of claim 1, wherein the quantity characterizing the exhaust gas purification system is a quantity directly measurable at the exhaust gas purification system, which is not measured at the exhaust gas purification system.
 7. The computer-implemented method of claim 6, wherein the quantity characterizing the exhaust gas purification system is a concentration of at least one pollutant in the exhaust gas stream to be purified which is fed into the exhaust gas purification system.
 8. The computer-implemented method of claim 7, wherein the concentration of the at least one pollutant in the exhaust gas stream to be purified is determined from one of the following subsets of the retrieved system data: a) measurement values of a carbon dioxide sensor of the exhaust gas purification system which measures a carbon dioxide concentration in a purified exhaust gas stream which is transmitted from the exhaust gas purification system; b) measurement values of an explosimeter of the exhaust gas purification system that measures a concentration of potentially explosive gases in the exhaust gas stream to be purified; or c) measurement values of a mass flow sensor of the exhaust gas purification system that measures a mass flow of a fuel used for a thermal oxidation of the exhaust gas stream to be purified.
 9. The computer-implemented method of claim 7, further comprising: determining a pollutant balance of the exhaust gas purification system for a predetermined period of time based on the determined concentration of the at least one pollutant in the exhaust gas stream to be purified.
 10. The computer-implemented method of claim 9, wherein the pollutant balance is further based on an individual measurement value, which is comprised in the retrieved system data, of a concentration of the at least one pollutant in a purified exhaust gas stream that is transmitted from the exhaust gas purification system.
 11. The computer-implemented method of claim 10, wherein the at least one pollutant is one or more solvents.
 12. The computer-implemented method of claim 1, wherein the quantity characterizing the exhaust gas purification system is an energy consumption of the exhaust gas purification system for a predetermined period of time and/or a predetermined operation mode of the exhaust gas purification system.
 13. The computer-implemented method of claim 12, wherein determining the energy consumption comprises the following: deriving from at least a part of the retrieved system data a quantity directly measurable at the exhaust gas purification system, which is not measured at the exhaust gas purification system; and determining the energy consumption based on the quantity derived.
 14. The computer-implemented method of claim 1, wherein the quantity characterizing the exhaust gas purification system is an amount of process heat that is generated or may be generated by the exhaust gas purification system in a predetermined period of time.
 15. The computer-implemented method of any of claim 1, wherein the quantity characterizing the exhaust gas purification system characterizes a separation process in the exhaust gas purification system in which at least one pollutant contained in the exhaust gas stream to be purified is separated.
 16. The computer-implemented method according to any of claim 1, wherein the quantity characterizing the exhaust gas purification system characterizes a concentration process in the exhaust gas purification system in which a concentration of at least one pollutant contained in the exhaust gas stream to be purified is increased.
 17. The computer-implemented method of any of claim 1, wherein the quantity characterizing the exhaust gas purification system characterizes a condensation process in which at least one pollutant contained in the exhaust gas stream to be purified is condensed.
 18. The computer-implemented method of any of claim 1, further comprising: outputting a message to at least a terminal device of a user when the quantity characterizing the exhaust gas purification system is outside a predetermined value range.
 19. The computer-implemented method of any of claim 1, further comprising: retrieving system data of a further exhaust gas purification system from the data cloud; determining the characterizing quantity for the further exhaust gas purification system based on the retrieved system data of the further exhaust gas purification system; and determining comparative information based on the characterizing quantity for the exhaust gas purification system and the characterizing quantity for the further exhaust gas purification system.
 20. A non-transitory, computer-readable medium comprising a program code for performing the computer-implemented method of claim 1, when the program code is executed on a processor or a programmable hardware component.
 21. A data processing system for monitoring the state of at least one exhaust gas purification system for purifying an exhaust gas stream to be purified of an industrial system or an industrial process, wherein the data processing system comprises at least one processor which is configured to: retrieve system data of the exhaust gas purification system from a data cloud, wherein the system data stored in the data cloud were at least partially received beforehand by the data cloud from the exhaust gas purification system, and wherein the system data relate to at least measurement data of at least one sensor of the exhaust gas purification system and/or data about at least one adjustable parameter of the exhaust gas purification system; and determine a quantity characterizing the exhaust gas purification system based on the retrieved system data.
 22. The data processing system of claim 21, wherein the data processing system is part of the data cloud.
 23. An exhaust gas purification system for purifying an exhaust gas stream to be purified of an industrial system or an industrial process, comprising: an inlet for feeding the exhaust gas stream to be purified into the exhaust gas purification system; an outlet for releasing a purified exhaust gas stream from the exhaust gas purification system; and a communication interface which is configured to send system data generated in the exhaust gas purification system to a data cloud, the system data relating to at least measurement data of at least one sensor of the exhaust gas purification system and data about at least one adjustable parameter of the exhaust gas purification system.
 24. The exhaust gas purification system of claim 23, further comprising at least one of the following devices: a concentration device configured to increase a concentration of at least one pollutant contained in the exhaust gas stream to be purified; a condensation device configured to condense at least one pollutant contained in the exhaust gas stream to be purified; and a separation device configured to separate at least one pollutant contained in the exhaust gas stream to be purified. 